Apparatus for measuring ohmic resistance of liquids and solutions



T. H. REARDON.

APPARATUS FOR MEASURING OHMIC RESISTANCE 0F LIQUIDS AND SOLUTIONS.

APPLICATION FILED NOV. 8| 19I8- I 1,346,057 nted July 6, 1920.

A TTORIVEI S "possibleintconsistent with economy in the use '0 salt. In the electrolytic production of hydrogen and oxygen by theele'ctrolysis of a solution of sodium hydrate (NaOH) the same reasoning holds good,

another factor that tendsto lower the TIMOTHY HENRY BEABDON, OF NORTH ADAMS, MASSACHUSETTS.

APPARATUS FOR MEASURING OHHIG RESISTANCE 0F LIQUIDS AND SOLUTIONS.

Specification of Letters Patent.

Patented July 6, 1920.

Application med November 8, 1918. Serial No; 261,672.

To all whom it may concern:

Be it known that I, TIMOTHY HENRY REARDON, a citizen of the United States, and a resident of North Adams, in the county of Berkshire and State of Massachusetts, have invented a new and Im roved Apparatus for Measuring Ohmic esistance of Liquids and Solutions, of which the followin is 'a full, clear, and exact description.

he object of the invention is to provide a new and improved a paratus for measuring ohmic resistance 0 liquids and solutions in a very simple, eflicient and quick manner, thus enabling the user 'to determine whether such liquid or solution is suitable for a particular purpose.

In the used electrolytes in batteries of both primary and secondary types, the ohmic resistance is a detriment as it is productive of heat and wasteful of electrical energy. Hydrometric readings fail to reveal the status of such liquids or solutions as regards their suitability in a battery. The absorption of carbon dioxid from the atmosphere in alkaline electrolytes tends to maintain the density of the electrolyte, while the loss of-solid substance which occurs as a result of spraying, gassing, etc., tends to lower the specific gravity. The resulting density thereof is dependent upon one factor that tends to increase the density and u on ensity. For thisreason'the' hydrometer reading by itself is. no criterion by which the character of the electrolyte can be jud ed.

In electrochemical work, such as the e ectrolysis of sodium chlorid (NaCl) for the production of sodium" hydrate (NaOI-lg, chlorin (Cl), sodiumh ochlorite (NaOCl sodium chlorate (NaC etc, it is of the greatest importance that. the ohmicresistance of the solution be kept at the lowest that ohmic resistance produces heat and is wasteful of electrical energy. With the apparatus presently described in detail the ohmic resistance of a liquid or solution can be quickly determined.

A practical embodiment of the invention is re resented in the accompanying drawing ormin a part of this specification, in which the gure is a sectional sideelevation of the apparatus with parts shown diagrammaticall The llquid or solution 10 of which the ohmlc resistance is to be determined is contalned in a vessel 11 of metal or other suitable conductive material. A tube 12 of glass or other non-conductive material is immersed with its lower end in the liquid 10 contained in the vessel 11, and the upper end of the tube 12 is provided with a metal d sk'13 having a small opening 14, and this dlsk 13' is he (1 in place on the tube by a ca 15 made of metal, carbon or other suitab e conductive material. The cap 15 is fitted tightly on the upper end of the tube by a packing ring 16 and the top of the cap 15 is provided with a short tube 17 -con- I nected with one end of a flexibletube 18 adapted to be connectedwith a suction device of any approved construction for drawing the liquid contained in the vessel 11 up in thetube 12 and into the cap 15. When this has been done the tube 18 is closed by a suitable closing device 19 to hold the liquid in column form in the tube 12. It is understood that the amount of' liquid contained in the tube 12 is predetermined'by using a correspondingly sized tube.

In order to determine the ohmic resistance of this column of liquid or solution contained in the tube 12, the following arrangement is made: A source of electrical energy is connected .by the circuit wires 25 and 26 with the pivots 27, 28 of a double blade, doublethrow switch 29 .of usual construction and adapted to be connected with contacts 30, 31 or 32, 33. The contacts 30, 31

are connected by wires 40, 41 with an indicajing device 42 such as a voltmeter, Wheatst .to read the voltage of-the current.

Thewire 41 is connected by a wire 45 with a brush 46 ofa-pole changing device 47 of usual construction and having provided with a pulley 49 connected by belt a Shaft 48 50 with other machinery'for rotating the shaft 48. On the shaft 48 are secured the,

cylinders or rings 51 and 52 having overouter end of the cylinder 52 is engaged byengaged by brushes 60, 61, of which the I brush 60 connects by a wire 62 with the vessel 11 and the brush 61 connects by a wire 63 with the cap 15. It will be noticed that when the switch 29 is disengaged from the contacts 30, 31 and swung into engagement with the contacts 32, 33 then an electric current passes from the main line to the vessel 11 through the liquid 10 to the cap 15 by way of the pole changer 47 and wires 45, 41 to the indicating device 42 to indicate the ohmic resistance of the liquid or solution contained in the tube 12. It is understood that by the use of the pole changer 4:? the electric current passing through the liquid or solution 10 in the tube 12 is rapidly reversed thus preventing development of polarization.

It will be noticed that by the arrange ment described the operator is enabled to first determine the voltage of the main current and then by the changing of the switch 29 and the sending of the current through the column of liquid or solution 10 a second reading is obtained at the indicating device 12 to indicate the voltage of the liquid. It

1 is understood that with the switch in lower position, the column of-liquid is placed in series with the indicating device 42 and a much lower voltage reading is obtained. It is understood that from the two readings obtained at the indicating device the electrical resistance of the column of liquid or I solution in the glass tube 12 can be readily calculated, it being known that in the case of distilled water contained in a tube twelve inches in length and of one quarter inch bore the electrical resistance is about 1,830,180 ohms. By making the length of the tube 12 sufficiently great and reducing the cross sectional area of the bore, the current passing through the liquid column can be made so infinitesimal-1y low in value that the counter electromotive force of polarization is practically m'l. I

It will be noticed that the apparatus is for the rapid measurement of resistance in a way that will appeal to the judgment and capacity of the ordinary man. A degree of accuracy is obtained that readily satisfies industrial requirements. Temperature errors .can be eliminated by making a test on a standard stock solution and a test on a sample both at the same time.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. An apparatus for measuring ohmic resistance of liquids and solutions, comprising a vessel of conductive material and adapted to contain the liquid or solution, a

tube of non-conductingmaterial having one end inserted in the said liquid or solution and adapted to be filled with the same, conducting material in contact with said liquid or solution at the other end of the tube, an electric circuit connected at one end with the said vessel and at its other end with the conducting material in contact with the liquidor solution, and means for measuring the voltage or potential difference of the said current in passing through the liquid or solution.

2. An apparatus for measuring ohmic resistance of liquids and solutions, comprising a vessel of conductive material and adapted to contain the liquid or solution, a tube of non-conducting material having one end inserted in the said liquid or solution and adapted to be filled with the same, conducting material in contact with said liquid or solution at the other end of the tube, an electric circuit connected at one end with the said vessel and at its other end with the conducting material, in contact with the liquid or solution, said electric circuit connected with a,source of electrical energy, a switch connected with the said circuit, an electric resistance indicating device connected with the said switch to permit of reading the voltage of the current of the said electric circuit when the switch is in one position, and a second circuit connected with the said indicating device and the said switch when the latter is in another position to permit of reading the voltage of the second circuit passing through the said column-of liquid or solution.

3. An apparatus for measuringohmic resistance of liquids and solutions, compris ing a vessel of conductive material and adapted to contain the liquid or solution, a

tube of non-conducting material having one end inserted in the said liquid or solution and adapted to be filled with the same, conducting material in contact with said liquid or solution at the other end of the tube, an electric circuit connected at one end with the said vessel and at its other end with the conducting material, in contact with the liquid or solution, said electric circuit connected with a source of electrical energy, a switch connected with the said circuit, an electric resistance indicating device connected with the said switch to persistance of liquids and solutions, comprising a vessel of conductive material and adapted to contain the liquid or solution, a tube of non-conducting material and having, its lower end inserted in the said liquid or solution, acap of conducting material and held on the upper end of the said tube, means connected With the said cap for drawing the liquid or solution up in the tube, an electric circuit connected at one end With 10 the said vessel and at its other end with the said cap, a voltmeter in the said circuit, a double switch in the said circuit, and a main or supply circuit connected with the said switch.

TIMOTHY HENRY REARDON. 

